Can A Bs88 Fuse Be Called A Main Switch For Cert. Purposes?

[sprocketflup]

Ive had a shufty through GN3, and my BGB and on site guide and cant find the answer to my current little dilemma.....

The set up is this - TNCS system, standard DNo cut-out, and then the tails from the cut out go straight to Henley blocks and split 3 ways, one to a Wylex rewireable board which is the daytime board, one to another rewireable board via a night meter, and then there is also a third enclosure added later on for a shower.(Via suitable meters and clocks)so only the shower is RCD protected at present.

My job is firstly change the RCD in the third board for a 30mA one ( 100mA at the mo) and then re-route the socket circuit to run from that board. (theres room, and the customer as usual wants to pay as little as possible)

so far so good.

Its the certificate that's got me confused. I was taught that the definition of Main Switch is a switch that will turn off the whole installation. Neither of the 'main switches' in the boards will do that, so on my certificate, where it asks for details of the main Switch, can/should I put the DNOs fuse details?

If not, how do I do this? 3 separate Certs? None of the boards are sub boards as they're all fed independently. Maybe list the 3 different versions of main switch that I have? Though Im sure I was taught that you only detail one Main Switch ....

Ill bet Im missing summat really simple here.....please excuse if so, its been a loooooooong weeeeeeekkkk

 

[steptoe]

yer,

my opinion would be,

1 installation,

1 main switch,

how about a linked REC4  ?  3 Lines and a N 

 

[sprocketflup]

**edit** I have no idea why the spellchecky thing has changed the word 'Main' to 'Mini' in the title???

Because its a spell checker for our furry friends ? :slap

 

[ProDave]

Post a picture of the setup.

I lost count at the third meter (for the shower CU) 

are you sure you are allowed to connect other circuits to that?

 

[Andy™]

a main switch does indeed isolate an installation.... but there is nothing to say you can only have 1 installation. so the main switch is the one covering the installation your working on, which would be the 61008

 

[sprocketflup]

Its not the set up that's confusing me tbh, just the certificate and definition of 'Main Switch'

**edit** so In your opinion it would need 3 seperate certs then Andy?

 

[steptoe]

are you only working on one board?

you could LIM the rest of the install

 

[ProDave]

I repeat my question, are you ALLOWED to connect socket circuits to that CU?

the only tariff I can think of with three metered circuits is the (no longer available) Total control Tariff.

that has a normal CU (metered cheap rate at night, peak rate in the daytime)  An off peak CU (metered off peak and only energised at night) and the "total control" circuit metered 24/7 at the cheap rate and ONLY to be used for heating appliances that includes showers.

your description of the shower CU "third enclosure added later on for a shower.(Via suitable meters and clocks)" suggests it's the total control CU.

Just warning.

 

[sprocketflup]

Owner wants a EICR coz she wants to rent it out, hence the socket circuit change. Im pretty sure shed leave it as is otherwise

I repeat my question, are you ALLOWED to connect socket circuits to that CU?

the only tariff I can think of with three metered circuits is the (no longer available) Total control Tariff.

that has a normal CU (metered cheap rate at night, peak rate in the daytime)  An off peak CU (metered off peak and only energised at night) and the "total control" circuit metered 24/7 at the cheap rate and ONLY to be used for heating appliances that includes showers.

Sorry Dave, I haven't explained very well by the look of it. Theres 2 meters, 1 for off peak (economy 7) and 1 for daytime, then 3 boards, nothing too unusual, ive just not had to certificate a set up like it before. like Steps said, if there was an isolater then I wouldn't have the problem Ive got, which is simply what to put under 'Main Switch' on the certificate. I only gave the other details to try and explain things and have just confused them haven't I?

The third 'board' is just a shower cu or garage cu that has been tacked on to the installation later, to modernise the bathroom with an electric shower, so im pretty sure its fine to do, but thanks for the warning. I haven't come across the setup you describe tbh

 

[Adrian]

were it says main switch list all 3  and say db 1 60947 db 2 4293 db 3 61008 ect  

read reg 537.1.3 and 537.1.4 

nowhere have I read it must be one switch and your set up is very common 

 

[ProDave]

If it's just henley'd off the feed to the main CU then no problem at all if there's space for another MCB.

I miss understood your description thinking it came from it's own meter.

 

[NozSpark]

The question you need to ask yourself is....

Does the installation have a main switch or not?

If it does, then list it,,, if it doesn't then put "None"

 

[SPECIAL LOCATION]

Its the certificate that's got me confused. I was taught that the definition of Main Switch is a switch that will turn off the whole installation. Neither of the 'main switches' in the boards will do that, so on my certificate, where it asks for details of the main Switch, can/should I put the DNOs fuse details?

To answer this bit of your question....

and if you ever have any doubt about other devices for switching isolation etc...

go to page 149  table 53.4

lists loads of devices and if they can be used for isolation / emergency switching / functional switching...

BS88's & BS1362 Fuses are listed

in both cases they are an acceptable means of Isolation..

BUT NOT a means of switching (emergency or functional)

So to list a BS88 as a "Main Switch" cannot be an acceptable selection...

Guinness